[PATCH v2 00/26] dmaengine: dw-edma: Add RP/EP local DMA controllers support

[Serge Semin <Sergey.Semin@baikalelectronics.ru>]

This is a final patchset in the series created in the framework of
my Baikal-T1 PCIe/eDMA-related work:

[1: In-progress v3] clk: Baikal-T1 DDR/PCIe resets and some xGMAC fixes
Link: https://lore.kernel.org/linux-pci/20220503205722.24755-1-Sergey.Semin@baikalelectronics.ru/
[2: In-progress v2] PCI: dwc: Various fixes and cleanups
Link: https://lore.kernel.org/linux-pci/20220503212300.30105-1-Sergey.Semin@baikalelectronics.ru/
[3: In-progress v2] PCI: dwc: Add dma-ranges/YAML-schema/Baikal-T1 support
Link: https://lore.kernel.org/linux-pci/20220503214638.1895-1-Sergey.Semin@baikalelectronics.ru/
[4: In-progress v2] dmaengine: dw-edma: Add RP/EP local DMA controllers support
Link: --you are looking at it--

Note it is recommended to merge this patchset after the former ones in
order to prevent merge conflicts. @Lorenzo could you merge in this
patchset through your PCIe repo? After getting all the ack'es of course
and after merging in the @Frank' series? (See the next paragraph for more
details.)

Please note originally this series was self content, but due to Frank
being a bit faster in his work submission I had to rebase my patchset onto
his one. So now this patchset turns to be dependent on the Frank' work:
Link: https://lore.kernel.org/linux-pci/20220503005801.1714345-1-Frank.Li@nxp.com/
So please merge Frank' series first before applying this one.

Here is a short summary regarding this patchset. The series starts with
fixes patches. The very first patch fixes the dma_direct_map_resource()
method, which turned out to be not working correctly for the case of
having devive.dma_range_map being non-empty (non-empty dma-ranges DT
property). Then we discovered that the dw-edma-pcie.c driver incorrectly
initializes the LL/DT base addresses for the platforms with not matching
CPU and PCIe memory spaces. It is fixed by using the pci_bus_address()
method to get a correct base address. After that you can find a series of
the interleaved xfers fixes. It turned out the interleaved transfers
implementation didn't work quite correctly from the very beginning for
instance missing src/dst addresses initialization, etc. In the framework
of the next two patches we suggest to add a new platform-specific
callback - pci_address() and use it to convert the CPU address to the PCIe
space address. It is at least required for the DW eDMA remote End-point
setup on the platforms with not-matching CPU/PCIe address spaces. In case
of the DW eDMA local RP/EP setup the conversion will be done automatically
by the outbound iATU (if no DMA-bypass flag is specified for the
corresponding iATU window). Then we introduce a set of the patches to make
the DebugFS part of the code supporting the multi-eDMA controllers
platforms. It starts with several cleanup patches and is closed joining
the Read/Write channels into a single DMA-device as they originally should
have been. After that you can find the patches with adding the non-atomic
io-64 methods usage, dropping DT-region descriptors allocation, replacing
chip IDs with the device name. In addition to that in order to have the
eDMA embedded into the DW PCIe RP/EP supported we need to bypass the
dma-ranges-based memory ranges mapping since in case of the root port DT
node it's applicable for the peripheral PCIe devices only. Finally at the
series closure we introduce a generic DW eDMA controller support being
available in the DW PCIe Host/End-point driver.

Link: https://lore.kernel.org/linux-pci/20220324014836.19149-1-Sergey.Semin@baikalelectronics.ru/
Changelog v2:
- Drop the patches:
  [PATCH 1/25] dmaengine: dw-edma: Drop dma_slave_config.direction field usage
  [PATCH 2/25] dmaengine: dw-edma: Fix eDMA Rd/Wr-channels and DMA-direction semantics
  since they are going to be merged in in the framework of the
  Frank's patchset.
- Add a new patch: "dmaengine: dw-edma: Release requested IRQs on
  failure."
- Drop __iomem qualifier from the struct dw_edma_debugfs_entry instance
  definition in the dw_edma_debugfs_u32_get() method. (@Manivannan)
- Add a new patch: "dmaengine: dw-edma: Rename DebugFS dentry variables to
  'dent'." (@Manivannan)
- Slightly extend the eDMA name array size. (@Manivannan)
- Change the specific DMA mapping comment a bit to being
  clearer. (@Manivannan)
- Add a new patch: "PCI: dwc: Add generic iATU/eDMA CSRs space detection
  method."
- Don't fail eDMA detection procedure if the DW eDMA driver couldn't probe
  device. That happens if the driver is disabled. (@Manivannan)
- Add "dma" registers resource mapping procedure. (@Manivannan)
- Move the eDMA CSRs space detection into the dw_pcie_map_detect() method.
- Remove eDMA on the dw_pcie_ep_init() internal errors. (@Manivannan)
- Remove eDMA in the dw_pcie_ep_exit() method.
- Move the dw_pcie_edma_detect() method execution to the tail of the
  dw_pcie_ep_init() function.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: Rob Herring <robh@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: linux-pci@vger.kernel.org
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Serge Semin (26):
  dma-direct: take dma-ranges/offsets into account in resource mapping
  dmaengine: Fix dma_slave_config.dst_addr description
  dmaengine: dw-edma: Release requested IRQs on failure
  dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address
  dmaengine: dw-edma: Fix missing src/dst address of the interleaved
    xfers
  dmaengine: dw-edma: Don't permit non-inc interleaved xfers
  dmaengine: dw-edma: Fix invalid interleaved xfers semantics
  dmaengine: dw-edma: Add CPU to PCIe bus address translation
  dmaengine: dw-edma: Add PCIe bus address getter to the remote EP
    glue-driver
  dmaengine: dw-edma: Drop chancnt initialization
  dmaengine: dw-edma: Fix DebugFS reg entry type
  dmaengine: dw-edma: Stop checking debugfs_create_*() return value
  dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor
  dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated
  dmaengine: dw-edma: Rename DebugFS dentry variables to 'dent'
  dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure
  dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor
  dmaengine: dw-edma: Join Write/Read channels into a single device
  dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory
  dmaengine: dw-edma: Use non-atomic io-64 methods
  dmaengine: dw-edma: Drop DT-region allocation
  dmaengine: dw-edma: Replace chip ID number with device name
  dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup
  dmaengine: dw-edma: Skip cleanup procedure if no private data found
  PCI: dwc: Add generic iATU/eDMA CSRs space detection method
  PCI: dwc: Add DW eDMA engine support

 drivers/dma/dw-edma/dw-edma-core.c            | 211 +++++-----
 drivers/dma/dw-edma/dw-edma-core.h            |  10 +-
 drivers/dma/dw-edma/dw-edma-pcie.c            |  24 +-
 drivers/dma/dw-edma/dw-edma-v0-core.c         |  76 ++--
 drivers/dma/dw-edma/dw-edma-v0-core.h         |   1 -
 drivers/dma/dw-edma/dw-edma-v0-debugfs.c      | 372 ++++++++----------
 drivers/dma/dw-edma/dw-edma-v0-debugfs.h      |   5 -
 .../pci/controller/dwc/pcie-designware-ep.c   |  16 +-
 .../pci/controller/dwc/pcie-designware-host.c |  17 +-
 drivers/pci/controller/dwc/pcie-designware.c  | 251 ++++++++++--
 drivers/pci/controller/dwc/pcie-designware.h  |  23 +-
 include/linux/dma/edma.h                      |  18 +-
 include/linux/dmaengine.h                     |   2 +-
 kernel/dma/direct.c                           |   2 +-
 14 files changed, 628 insertions(+), 400 deletions(-)

-- 
2.35.1